A century-and-a-half ago, Tulare Lake was about 500 to 700 square miles of water – more than three times the size of Lake Tahoe, depending on how much rain or snow fell in a given year. It was the largest freshwater lake west of the Mississippi, the end of the continent’s southernmost Chinook salmon run, and home to one of the most prosperous native tribes in California.
Today there is no lake. Its Sierra Nevada tributary waters were long ago diverted for irrigation, beginning after the Civil War and finally ending with five major water projects built in the 1930s. The area the lake once occupied – the Tulare Basin, in the southwest quadrant of California’s Central Valley – is home to some of the state’s most fertile farmland. It’s also among the state’s most arid regions.
This contradiction has never been lost on Californians. Over decades, they’ve engineered a byzantine system of water capture, diversion, and redistribution that has transformed the Central Valley – with its Mediterranean climate, rich soils, and steady supply of Sierra Nevada snowmelt – into one of the most productive agricultural regions in the world. California produces more than half the nation’s fruits and vegetables.
Since its inception, the system has suffered periods of noticeable strain. Before the dry spell that began in 2012 – the third-worst on record so far, a drought that has caused the price of irrigation water to spike in some districts by a factor of 10 – California’s farmers and ranchers had already become some of the nation’s most careful stewards of water. Brian Medeiros, a dairyman who raises 2,500 cows on 1,400 acres at the northern edge of the former Tulare Lake, near the town of Hanford, has always had to conserve. “We use a good chunk of water on the dairy to cool the cows, wash the cows, cool the milk down, clean the areas where the cows are milked, and then also clean their housing. All that water at the end of the day turns into irrigation water.” Medeiros estimates that about 100 to 200 acre-feet are captured every summer, treated, and recycled into irrigation water.
Over the past four years, however, Medeiros has had increasingly less water to capture. He and his neighbors purchase water from a private ditch operator that distributes through a canal system. In 2011, he said, when the state received good rainfall, his dairy received a surplus of water. “But it’s been downhill since. In 2012, we had about 80 percent of our normal allocation; in 2013, we had about 50 percent. Then in 2014, we had 11 percent. And this year we didn’t get a single drop. We received absolutely no surface water.”
There was little surface water to go around. By spring 2015, the Sierra snowpack, which supplies about a third of the state’s useable water, was at 5 percent of its average, an all-time low. Gov. Edmund Gerald “Jerry” Brown Jr. had recently issued his second executive order to the state’s municipalities to cut their water use by 25 percent, and for the second year in a row, the U.S. Bureau of Reclamation announced that most Central Valley farmers south of the Sacramento-San Joaquin River Delta would receive no water from the federal Central Valley Project. By August, the State Water Project was delivering about 20 percent of its promised allotment.
In August 2015, the Center for Watershed Sciences at the University of California-Davis released an analysis of the economic impact the drought was likely to have on California agriculture. Among its conclusions: The direct and indirect losses to all economic sectors would be as high as $2.74 billion, with a net loss of nearly 21,000 jobs. The total surface water shortages, virtually all of them suffered by Central Valley farmers, would amount to nearly 8.7 million acre-feet.
Given such grim numbers, how have farmers and ranchers like Medeiros managed to stay in business? It’s worth pointing out that many California farmers and ranchers were more ready than most people expected to adapt to a prolonged drought. But even so, nobody thinks the solutions being used in the Central Valley today – each of which involves its own costs – are going to be sustainable over the long term.
A Show of Resilience
One of the simplest responses to the drought has been to let land go fallow. According to the UC-Davis report, about 540,000 acres of California farmland went unplanted in 2015 because of the drought. “The rest of the country was up,” said Daniel Sumner, Ph.D., professor of agricultural and resource economics at UC-Davis and co-author of the report. “So that’s a sign that this wasn’t a national phenomenon driven by price.”
The Central Valley is often discussed as two distinct regions: the Sacramento Valley, north of the Delta, and the more arid San Joaquin Valley, which stretches south to Bakersfield. Idling was most prevalent, Sumner said, in the San Joaquin, where commodity crops such as cotton or corn silage are grown. Growers of alfalfa, a water-intensive silage crop, have been able to keep farming – but as Sumner explained, that’s because it’s a grassy legume: “You water, you mow it, you water, you mow it. You can cut alfalfa up to seven or eight times a year.” This year, alfalfa growers have scaled their cuttings back to about four.
Obviously, one of the most significant changes to the way Central Valley farmers are operating in the drought is their sourcing of water. Many farmers have found it more profitable to transfer their allotments to others, in districts where it’s permissible. According to the UC-Davis report, the 2015 price for irrigation water averaged about $650 per acre-foot, making it more profitable for traditional growers of thirsty crops, such as Sacramento Valley rice farmers, to simply sell their water, often to farmers farther south.
Determining how much water is allotted to growers in California is complicated, a maze of different public and private adjudications that date to the mid-19th century. But Dave Puglia, executive vice president of the Western Growers Association, a trade association of California, Arizona, and Colorado farmers founded in 1926, said that Central Valley growers generally relied on surface water to the greatest extent possible.
“In any event, no matter how much surface water you’re able to cobble together,” said Puglia, “if you’re in the San Joaquin Valley, you’ve probably turned more heavily to groundwater. You may have dropped new wells. You may have deepened existing wells. You’re pumping much more water from much greater depth than you ever have before – and in many cases, the quality of that water is worsening because as a rule, the deeper you go, the saltier the water coming up.”
The UC-Davis report projected that the 2015 shortage of 8.7 million acre-feet would be mostly offset by a 6 million acre-feet increase in groundwater pumping over the 2011 pre-drought baseline. In addition to the declining quality of this water, this surge in extraction involves other costs: According to Josué Medellín-Azuara, a senior researcher at the UC-Davis Center for Watershed Sciences, farmers will pay 77 percent more – $600 million – this year simply to pump water out of the ground. Another related problem is land subsidence, or the sinking of land overlying aquifers as water is pumped out. In August 2015, scientists with NASA’s Jet Propulsion Laboratory released a report, based on satellite imaging, that showed significant recent subsidence. A site near Corcoran, in the Tulare Basin, sank 13 inches over eight months. A stretch of the California Aqueduct, the main artery of the State Water Project, sank 8 inches over four months. Sections of the Delta-Mendota Canal, which supplies much of the San Joaquin Valley, have buckled and had to be propped back up.
The idea that pumping groundwater could help wreck the state’s surface water infrastructure is a grim irony, but many farmers don’t have much choice. With no surface water available, Medeiros has had to rely on groundwater to produce forage for his dairy cows. To ease the demand for water, he’s replacing corn and wheat with sorghum and a drought-hardy wheat/rye hybrid called triticale.
As Puglia pointed out, the water Medeiros uses is likely to become more saline as the water table drops. The risks associated with groundwater pumping are serious enough that the state finally passed its first groundwater management bill last fall, ordering local jurisdictions to draw up regulations – but the earliest deadline for establishing most of those regulations isn’t until 2020. Meanwhile some jurisdictions – including the Sacramento Valley’s main rice-growing counties, Glenn and Colusa – have set temporary moratoriums on permits for new wells.
One of the drought-adaptation strategies often mentioned in news reports – crop switching – is difficult to quantify, for several reasons. First, Sumner pointed out, it’s not a new strategy. “It’s been going on for 50 years,” he said. “Did it accelerate a bit because of the drought? We actually don’t know, because there were a lot of market things going on as well.” In those 50 years, California farmers have tended to drift away from annual commodity crops such as corn, cotton, and rice, and more toward higher-value crops such as fruits, nuts, and vegetables. In the past year, California newspapers have featured multiple stories of farmers switching, say, from cotton to almonds – now one of the state’s most valuable crops.
Puglia said San Joaquin growers have taken this shift a step further: “You’ve got a lot of growers who have reduced their plantings of processing tomatoes or cantaloupes or broccoli, and they’re now growing almonds and pistachios and walnuts and grapes,” he said. “And that’s understandable. Those crops are more lucrative. You get more dollars per acre, but you’re taking some risk that you won’t be able to stop watering in times of scarcity, because you’ll lose the investment. So those folks are pinched. They’re the ones who are spending upwards of $1,250, all the way up to $2,000 an acre-foot, for water on the market.”
Puglia believes that after a certain point, there’s not much more farmers can do to conserve water and meet demand for their crops – and he believes the drought is only part of California agriculture’s problem, a symptom of a much larger systemic failure that’s occurred over the past few decades. A series of lawsuits, regulations, and court actions have gradually shifted water away from the agricultural budget. A commonly cited statistic is that agriculture uses 80 percent of the state’s water – but that’s only when human uses of water are accounted for. The Public Policy Institute of California (PPIC) sorts out the total, roughly, as follows: 50 percent of the state’s surface water is used to comply with environmental laws and regulations; 40 percent of it is used by agriculture; and 10 percent is consumed by urban areas.
It’s not simply that agriculture’s share of the state’s surface water has shrunk overall, Puglia said; it’s that existing laws and regulations prevent farmers from banking more water in times of plenty, even when all other requirements and environmental compliances have been satisfied. It’s an inefficient and inflexible system that he’d like to see reformed. “Interestingly,” he said, “water managers in California are starting belatedly right now to talk about not missing the opportunity that El Niño might provide this winter. If we do get heavy precipitation, especially if it comes in the form of rain and not snow in the Sierras, we’re going to see floodwaters coming down into the valley. And you see people at PPIC and UC-Davis sort of ringing the alarm bell and saying, if that water shows up, we’ve got to find farms to flood and allow groundwater basins to recharge.”
He’s not optimistic that there’s enough time, however, for the bureaucratic gears to turn: “I think what we’re going to see this year is millions of acre-feet of water channeled out underneath the Golden Gate that could have been either spread on grounds for recharge of basins, or pumped south of the Delta and captured in one of our biggest reservoirs in the state, San Luis Reservoir near Los Banos.” Under federal environmental laws, the reservoir’s pumping facilities can’t be operated at full capacity, even in times of flood.
Beyond this winter, Puglia hopes for structural fixes to a system that has Central Valley farmers, especially those in the south, caught in a vicious cycle: Because California farmers have become so efficient at irrigating over the years, there’s very little water seeping beneath the root zone into aquifers. “While you’re causing less water to be sent back into the groundwater basin,” said Puglia, “you’re increasing their reliance on groundwater, because you’ve cut off surface water. It’s really distressing. Unless we regain some balance in the way we manage water, we’re probably looking, over time, at a much-reduced level of agricultural activity in the San Joaquin Valley.”
Caption for top photo: An irrigation ditch runs dry near Grizzly Island Road in Suisun City, California, Sept. 18, 2014. Credit: Photo by Florence Low
This article was originally published in the 2016 edition of U.S. Agriculture Outlook.